How to Fix the WpnUserService.dll Error on Windows

Windows users who encounter the WpnUserService.dll error may no longer receive important notifications on the system. The error is caused by problems with the WpnUserService.dll file that is responsible for the notifications sent by Windows or other applications to work properly. The file is located in the protected C:\Windows\System32\ location that needs admin privileges for access. To fix the WpnUserService.dll error, you may need to try several fixes until you find the right one. 

Restart the WPNU service

1. Press the Windows key + R on your keyboard. 
2. In the Run dialog box, type services.msc and press Enter.
3. In the window, locate WPNService and double-click it.
4. If the service is not running, start it. If it is already active, then stop and restart it.
5. Also, make sure that the startup type is set to 'Automatic' from the drop-down menu. 

Perform an SFC scan

1. Type command prompt in the search field on the taskbar and open it with admin privileges.
2. In the elevated Command Prompt window, type SFC /scannow and press Enter.
3. The System File Checker will scan your computer and fix any corrupted or missing files that are essential for the proper functioning of the Windows OS. Wait for the process to finish. 

Run a DISM scan

If SFC found no issues but the WpnUserService.dll error still appears, try running a  Deployment Image Servicing and Management (DISM) scan.

1. Open an elevated Command Prompt again.
2. This time type the dism /online /cleanup-image /restorehealth command and press Enter to execute it.
3. Wait for the scan to complete and for any detected errors to be fixed. Check if the WpnUserService.dll error has been resolved.